In a heavy saucepan, melt butter. Stir in marshmallows; cook and stir over low heat until melted. Remove from the heat; stir in cereal and pecans. Let cool just enough to handle.

With greased hands, shape into trees. (Work quickly as the cereal hardens quickly and becomes difficult to form.) Roll in green sugar. Place on a serving tray; dust with confectioners' sugar. Yield: about 1-1/2 dozen.